Dani Pedrosa one again headed title rival Jorge Lorenzo in MotoGP's second Friday practice session at Laguna Seca.

As the pace increased, so did the accidents. Gresini's Alvaro Bautista, Tech 3 Yamaha's Cal Crutchlow and Ducati's Valentino Rossi all fell – the latter bringing out the red flags as his bike pierced the air fence on the outside of Turn 3.

All were unhurt in the accidents however, and Rossi was one of the first out when the session resumed with just over 10 minutes to run.

There were to be no changes to the top order though, with Pedrosa securing top spot from Yamaha's Lorenzo and his works Honda team-mate Casey Stoner. The Honda pair found marked improvements from the morning session, while Lorenzo's gains were more modest.

Fourth to sixth didn't change from the opening practice, with Ben Spies leading the satellite Tech 3 Yamahas of Andrea Dovizioso and Cal Crutchlow.